1. The Field of the Invention
The present invention relates to electronic communications. Specifically, the present invention relates to methods and systems for message forwarding and property notification using electronic subscriptions.
2. The Prior State of the Art
Electronic communication technology has advanced significantly in modern times. Currently, information is commonly exchanged over computer networks. The largest and most far reaching of all computer networks has been termed "the Internet" which links devices worldwide. The Internet is essentially composed of a worldwide network of interlinked computer servers. Other smaller networks ("intranets") used to link local devices in, for example, a company or organizational environment are termed local area networks (LANs). LANs may also be interconnected to each other over the Internet.
Communication over the Internet can occur in several ways. A sender may send an unsolicited message to the recipient via, for example, e-mail. While such unsolicited e-mail often contains desired information, the e-mail might also contain information that is not desired or not timely. Thus, recipients often generate a request focussed on desired information. For example, a user may use an Internet browser and type in a uniform resource locator (URL) address corresponding to a piece of desired information such as, for example, a stock price residing on a remote server. The user then submits the request over the Internet using a protocol such as HyperText Transport Protocol (HTTP). Upon receiving the request, the remote server transmits the data back to the user's Internet browser.
While the requested information may be desired, the information may still not be timely. After all, the user only periodically checks for the desired information since a request must be generated to check for the desired information. If the user checks for the desired information once every hour, for example, the information may be as much as one hour old before the user again requests updated data. That kind of old data may be useless in many applications. Thus, what was desired is a way of obtaining real-time information over the Internet from remote devices.
One way for a user to obtain information over the Internet from a remote device is to subscribe to information on a device containing Internet broadcasting capability. For instance, a remote server may broadcast information such as stock prices, files and video to a wide number of users over the Internet. One disadvantage of such a system is that the remote system must have expensive and complicated broadcasting capability. There are only a limited number of such systems available. Often, it is desirable to obtain information from a device or server that does not have powerful broadcasting capability.
Buddy lists allow for a user to obtain information, albeit limited to online status, in relative real-time from a remote device. Buddy lists are known in the context of instant messaging systems. Instant messaging requires the tracking of the online status of each user in a buddy list since instant messaging in real-time requires that each correspondent be online. If a correspondent is listed as off-line, users who have the correspondent listed in their buddy list will then know not to waste time trying to engage in a real-time conversation with the off-line correspondent. On the other hand, if the correspondent is online, users who have the correspondent listed in their buddy list will know that they can engage in real-time conversation with the correspondent (assuming the correspondent is willing).
Instant messaging systems do not give any other information about the remote device other that online status. After all, online status is the only information about remote devices that is needed in instant messaging. It is also relatively simple to determine the online status. The buddy lists ping each other at short intervals to see who's online. If the ping is successful, the client reports that your buddy is online and ready to chat. These methods are specifically tailored to determining online status.
In addition to the disadvantage of only providing online status, many instant messaging systems have difficulty communicating through firewalls depending on the firewall characteristics. Firewalls are machines commonly used for enforcing corporate network security policies; most business users connect to the Internet through a firewall. Firewalls represent a significant impediment to real-time communication between Internet users. Firewall designs generally prohibit external entities on the Internet from directly connecting to internal entities protected by the firewall. While such security mechanisms prevent external entities from maliciously manipulating internal entities, they have had the side effect of preventing asynchronous communication to an internal entity.
In light of the above shortfalls, what is desired is a method and system for determining a wide variety of information about a remote device in real-time even if the remote device does not have complicated broadcasting capability, and even if the remote device is on the other side of a firewall.